P0264

Cylinder 2 Injector Circuit Low

Indicator

The PCM has detected a voltage reading in the fuel injector circuit (for the fuel injector in cylinder 2) that does not conform to the manufacturer’s reference value.

Code Set Parameters

Voltage variations (caused by inadvertent resistance) that exceed 10-percent of the manufacturer’s referenced voltage will cause a code to be stored in the PCM and a malfunction indicator lamp to be illuminated.

Symptoms

These could include rough idle, choppy acceleration, an engine misfire, a stored code in the PCM, and an illuminated service engine soon lamp.

Common Causes

The most common cause of this code is damage to wiring caused by wildlife. The warm area atop the engine provides shelter for small animals, where they proceed to gnaw the wiring for some strange reason. Other causes include a faulty fuel injector, clogged fuel injector, corroded or loose electrical wiring or connector faces, or a faulty fuel injector driver in the PCM.

Common Misdiagnosis

Keep in mind that PCM failure is rare. Often the PCM is replaced in error because of open or shorted circuits in the fuel injection system or faulty fuel injectors.

Diagnosis

The majority of modern automotive fuel injectors are actuated via a locking two-wire electrical connector

They are supplied with a constant supply of voltage (comparable to that of the battery), through a fused power wire

The circuit is completed by the second wire which is grounded by the fuel injector driver in the PCM (or other suitable controller) in the form of regulated pulses

When the circuit is completed, the fuel injector is activated and a spray of fuel is injected into the individual cylinders (multi-port fuel injection) or throttle body (throttle body injection).
A scanner (or code reader), a digital volt/ohmmeter, a suitable “noid lamp” and a manufacturer’s service manual (or the equivalent) will be helpful in successfully diagnosing this code-storing condition.
Begin your diagnosis with a visual inspection of all wiring and connectors

Always retest the system after repairs are completed to ensure success.
If all system wiring, connectors, and components (Including fuses) appear to be in normal working order, connect the scanner (or code reader) to the diagnostic connector and record all stored codes and freeze frame data

This information can be extremely helpful in diagnosing intermittent conditions that may have contributed to this code being stored

After the codes are cleared, operate the vehicle to see if the code returns

If the code fails to immediately return, you may have an intermittent condition

Intermittent conditions can prove to be quite a challenge to diagnose and in extreme cases may have to be allowed to worsen before a correct diagnosis can be made.
Use the digital volt/ohmmeter to test the constant power supply to the particular fuel injector group (key on-engine off)

If there is no battery voltage detected at the fuel injector group connector, check system fuses and relays

Repair faulty components as required, clear the code and retest the system to ensure that the repair was successful

NOTE: Carefully test fuses under load

Fuses that appear to be working normally with the key on and the engine off may fail when the engine is cranked

Poor connections in the fuse panel can often be contributed to this condition

If the fuses and relays appear to be intact, disconnect the connector from the PCM (and other related controller/s) and perform a continuity and resistance test on all related circuits

Repair or replace open or shorted circuits, connectors, or components as required

Clear the codes and test drive the vehicle to ensure a successful repair

If the power supply is present at the fuel injector connector/s or harness connector/s, use a “noid lamp” to check for a ground pulse from the PCM

If no ground pulse is detected, disconnect the electrical connector from the PCM (and other related controller/s) and perform a continuity and resistance test on all circuits

Repair open or shorted electrical wiring, connectors, or components as required then clear the code and retest the system

If all circuits appear to be intact, suspect a faulty injector driver in the PCM

PCM failure is rare and replacement will require reprogramming of one or more controllers.
If a constant power supply and a ground pulse are present, use a listening device to determine whether the injector or injectors in question are being activated

This will help you to determine if individual injectors are functioning and spraying fuel into the cylinder

If an audible “ticking” noise is heard when the injector is energized, the injector is likely to be operating normally (unless flow is restricted)

If no audible tick is heard when the injector is energized, suspect a faulty fuel injector

Remove the electrical connector from the injector and perform a resistance test on the injector